Deploy a PostgreSQL Flexible Server Database using Terraform

Article
10/26/2023

Article tested with the following Terraform and Terraform provider versions:

Terraform enables the definition, preview, and deployment of cloud infrastructure. Using Terraform, you create configuration files using HCL syntax. The HCL syntax allows you to specify the cloud provider - such as Azure - and the elements that make up your cloud infrastructure. After you create your configuration files, you create an execution plan that allows you to preview your infrastructure changes before they're deployed. Once you verify the changes, you apply the execution plan to deploy the infrastructure.

This article shows how to deploy a PostgreSQL Flexible Server Database using Terraform.

In this article, you learn how to:

Create an Azure resource group using azurerm_resource_group
Create an Azure virtual network (VNet) using azurerm_virtual_network
Create an Azure Network Security Group (NSG) using azurerm_network_security_group
Create an Azure subnet azurerm_subnet
Create an Azure subnet Network Security Group (NSG) using azurerm_subnet_network_security_group_association
Define a private DNS zone within an Azure DNS using azurerm_private_dns_zone
Define a private DNS zone VNet link using using azurerm_private_dns_zone_virtual_network_link
Deploy an Azure PostgreSQL Flexible Server on which the database runs using azurerm_postgresql_flexible_server
Instantiate an Azure PostgreSQL database using azurerm_postgresql_flexible_server_database

Note

The example code in this article is located in the Azure Terraform GitHub repo.

1. Configure your environment

Azure subscription: If you don't have an Azure subscription, create a free account before you begin.

Configure Terraform: If you haven't already done so, configure Terraform using one of the following options:

2. Implement the Terraform code

Create a directory in which to test and run the sample Terraform code and make it the current directory.

Create a file named providers.tf and insert the following code:

terraform {
  required_version = ">=1.0"

  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = "~>3.0"
    }
    random = {
      source  = "hashicorp/random"
      version = ">= 3.4.0"
    }
  }
}

provider "azurerm" {
  features {}
}

Create a file named main.tf and insert the following code to deploy the PostgreSQL Flexible Server on which the database runs.

resource "random_pet" "name_prefix" {
  prefix = var.name_prefix
  length = 1
}

resource "azurerm_resource_group" "default" {
  name     = random_pet.name_prefix.id
  location = var.location
}

resource "azurerm_virtual_network" "default" {
  name                = "${random_pet.name_prefix.id}-vnet"
  location            = azurerm_resource_group.default.location
  resource_group_name = azurerm_resource_group.default.name
  address_space       = ["10.0.0.0/16"]
}

resource "azurerm_network_security_group" "default" {
  name                = "${random_pet.name_prefix.id}-nsg"
  location            = azurerm_resource_group.default.location
  resource_group_name = azurerm_resource_group.default.name

  security_rule {
    name                       = "test123"
    priority                   = 100
    direction                  = "Inbound"
    access                     = "Allow"
    protocol                   = "Tcp"
    source_port_range          = "*"
    destination_port_range     = "*"
    source_address_prefix      = "*"
    destination_address_prefix = "*"
  }
}

resource "azurerm_subnet" "default" {
  name                 = "${random_pet.name_prefix.id}-subnet"
  virtual_network_name = azurerm_virtual_network.default.name
  resource_group_name  = azurerm_resource_group.default.name
  address_prefixes     = ["10.0.2.0/24"]
  service_endpoints    = ["Microsoft.Storage"]

  delegation {
    name = "fs"

    service_delegation {
      name = "Microsoft.DBforPostgreSQL/flexibleServers"

      actions = [
        "Microsoft.Network/virtualNetworks/subnets/join/action",
      ]
    }
  }
}

resource "azurerm_subnet_network_security_group_association" "default" {
  subnet_id                 = azurerm_subnet.default.id
  network_security_group_id = azurerm_network_security_group.default.id
}

resource "azurerm_private_dns_zone" "default" {
  name                = "${random_pet.name_prefix.id}-pdz.postgres.database.azure.com"
  resource_group_name = azurerm_resource_group.default.name

  depends_on = [azurerm_subnet_network_security_group_association.default]
}

resource "azurerm_private_dns_zone_virtual_network_link" "default" {
  name                  = "${random_pet.name_prefix.id}-pdzvnetlink.com"
  private_dns_zone_name = azurerm_private_dns_zone.default.name
  virtual_network_id    = azurerm_virtual_network.default.id
  resource_group_name   = azurerm_resource_group.default.name
}

resource "random_password" "pass" {
  length = 20
}

resource "azurerm_postgresql_flexible_server" "default" {
  name                   = "${random_pet.name_prefix.id}-server"
  resource_group_name    = azurerm_resource_group.default.name
  location               = azurerm_resource_group.default.location
  version                = "13"
  delegated_subnet_id    = azurerm_subnet.default.id
  private_dns_zone_id    = azurerm_private_dns_zone.default.id
  administrator_login    = "adminTerraform"
  administrator_password = random_password.pass.result
  zone                   = "1"
  storage_mb             = 32768
  sku_name               = "GP_Standard_D2s_v3"
  backup_retention_days  = 7

  depends_on = [azurerm_private_dns_zone_virtual_network_link.default]
}

Create a file named postgresql-fs-db.tf and insert the following code to instantiate the database:

resource "azurerm_postgresql_flexible_server_database" "default" {
  name      = "${random_pet.name_prefix.id}-db"
  server_id = azurerm_postgresql_flexible_server.default.id
  collation = "en_US.utf8"
  charset   = "UTF8"
}

Create a file named variables.tf and insert the following code:

variable "name_prefix" {
  default     = "postgresqlfs"
  description = "Prefix of the resource name."
}

variable "location" {
  default     = "eastus"
  description = "Location of the resource."
}

Create a file named outputs.tf and insert the following code to output the resource group name, Azure PostgreSQL server name, and Azure PostgreSQL database name:

output "resource_group_name" {
  value = azurerm_resource_group.default.name
}

output "azurerm_postgresql_flexible_server" {
  value = azurerm_postgresql_flexible_server.default.name
}

output "postgresql_flexible_server_database_name" {
  value = azurerm_postgresql_flexible_server_database.default.name
}

output "postgresql_flexible_server_admin_password" {
  sensitive = true
  value     = azurerm_postgresql_flexible_server.default.administrator_password
}

3. Initialize Terraform

Run terraform init to initialize the Terraform deployment. This command downloads the Azure provider required to manage your Azure resources.

terraform init -upgrade

Key points:

The -upgrade parameter upgrades the necessary provider plugins to the newest version that complies with the configuration's version constraints.

4. Create a Terraform execution plan

Run terraform plan to create an execution plan.

terraform plan -out main.tfplan

Key points:

The terraform plan command creates an execution plan, but doesn't execute it. Instead, it determines what actions are necessary to create the configuration specified in your configuration files. This pattern allows you to verify whether the execution plan matches your expectations before making any changes to actual resources.
The optional -out parameter allows you to specify an output file for the plan. Using the -out parameter ensures that the plan you reviewed is exactly what is applied.

5. Apply a Terraform execution plan

Run terraform apply to apply the execution plan to your cloud infrastructure.

terraform apply main.tfplan

Key points:

The example terraform apply command assumes you previously ran terraform plan -out main.tfplan.
If you specified a different filename for the -out parameter, use that same filename in the call to terraform apply.
If you didn't use the -out parameter, call terraform apply without any parameters.

Run az postgres flexible-server db show to display the Azure PostgreSQL database.

az postgres flexible-server db show --resource-group <resource_group_name> --server-name <server_name> --database-name <database_name>

Key points:

The values for the <resource_group_name>, <server_name>, and <database_name> are displayed in the terraform apply output.

Run Get-AzPostgreSqlFlexibleServerDatabase to display the Azure PostgreSQL database.

Get-AzPostgreSqlFlexibleServerDatabase -ResourceGroupName <resource_group_name> -ServerName <server_name> -Name <database_name>

Key points:

The values for the <resource_group_name>, <server_name>, and <database_name> are displayed in the terraform apply output.

7. Clean up resources

When you no longer need the resources created via Terraform, do the following steps:

Run terraform plan and specify the destroy flag.
```
terraform plan -destroy -out main.destroy.tfplan
```
Key points:
- The terraform plan command creates an execution plan, but doesn't execute it. Instead, it determines what actions are necessary to create the configuration specified in your configuration files. This pattern allows you to verify whether the execution plan matches your expectations before making any changes to actual resources.
- The optional -out parameter allows you to specify an output file for the plan. Using the -out parameter ensures that the plan you reviewed is exactly what is applied.
Run terraform apply to apply the execution plan.
```
terraform apply main.destroy.tfplan
```

Troubleshoot Terraform on Azure

Troubleshoot common problems when using Terraform on Azure

Next steps

Learn more about PostgreSQL Flexible Server

Deploy a PostgreSQL Flexible Server Database using Terraform

1. Configure your environment

2. Implement the Terraform code

3. Initialize Terraform

4. Create a Terraform execution plan

5. Apply a Terraform execution plan

6. Verify the results

7. Clean up resources

Troubleshoot Terraform on Azure

Next steps

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Additional resources